The New York Times reported that Brazilian military officials sent two C-130 cargo planes to the northwestern state of Rondônia. Troops were expected to assist firefighting efforts there and in the states of Pará, Tocantins, Roraima, Acre and Mato Grosso.

Military officials on Saturday said a task force would determined how the armed forces can best assist in the battle.

Bolsonaro on Friday announced his intention for the Brazilian military to step in to help emergency and environmental agencies contain the fires, and he warned foreign powers against meddling.

"The Brazilian Amazon is a heritage of our people, who will protect it from the threats of those who harm the forest with illegal actions and will react to those who intend to violate our sovereignty, " Bosonaro's announcement said.

President Donald Trump on Friday offered to help Brazil combat Amazon rainforest fires.

Trump said that the United States' relationship with the South American country is "perhaps stronger than ever" in a tweet in which he offered help after he spoke with Bolsonaro.

"Our future trade prospects are very exciting and our relationship is strong, perhaps stronger than ever before," Trump tweeted. "I told him if the United States can help with the Amazon rainforest fires, we stand ready to assist!"

Amnesty International also urged Bolsonaro on Thursday to take action, adding that he is responsible because he implemented measures to weaken deforestation protections.

Trump and Bolsonaro, a right-wing populist, have advocated using previously protected natural areas for resources.

Brazil's Amazon rainforest has been burning at a record rate, satellite data from the Brazil National Institute for Space Research showed Tuesday with 72,843 fires in Brazil this year, more than half of them in the Amazon region. The number of wildfires this year is an 84 percent increase from the same period last year.